Air motor



United States Patent inventor Donald E. Darnell Northville, Michigan (5740 Chase Road, Dearborn, Mich. 48126) Appl. No. 732,183 Filed May 27, 1968 Patented Sept. 15, 1970 AIR MOTOR 18 Claims, 7 Drawing Figs.

U.S. C1 91/26, 91/394, 91/446, 91/448 Int. Cl. ..F15b 15/22, v Fl5b11/O8,F15b13/O4 Field of Search 91/26,

394 (Cursory), 395 (Cursory), 3 96 (Cursory) References Cited UNITED STATES PATENTS Wertman et a1.

Hoanes Norwood. Aslan Mercier Primary ExaminerPaul E. Maslousky Attorney-Barnes, Kisselle, Raisch and Choate ABSTRACT: The air motor disclosed herein comprises a" cylinder having substantially identical heads that have axial and transverse passages therein which are adapted to be selectively provided with valves so that one or both ends can be adapted for cushioning or speed control or combined cushioning and speed control.

Patented Sept. 15, 1910 3,523,339

FIG. '7

ATTORNEYS AIR MOTOR This invention relates to fluid actuators and particularly to air motors of the type used for moving parts such as welding clamps and the like into and out of the position.

Among the objects of the invention are to provide a small air motor which can be adapted to provide speed control and cushioning independently of one another; wherein either end of the cylinder can be readily converted to include or exclude cushioning or speed control; which is of standard size and requires no increase in length thereof to accommodate the cushioning or speed controls; which is relatively compact; can be readily shut off to lock the piston in any position for adjustment of the mechanism associated therewith; which utilizes a basic length that is not increased by adding a cushioning or speed control thereto; which is relatively low in cost and simple in operation; wherein when the cushioning and speed control are positioned to be ineffective, substantially no restriction to the movement of the air occurs and the air motor will operate in such a manner as if it were a standard cylinder without cushioning and speed controls.

In the drawings:

FIG. 1 is a part sectional longitudinal view of a fluid motor embodying the invention.

FIG. 2 is a sectional view taken along the line 22 in FIG. 1.

FIG. 3 is a fragmentary sectional view taken along theline 3-3 of FIG. 2.

FIG. 4 is a fragmentary sectional view taken along the line 4-4 of FIG. 2.

FIG. 5 is a fragmentary sectional view taken along the line 55 in FIG. 1.

FIG. 6 is a fragmentary plan view of a portion of the device shown in FIG. 5.

FIG. 7 is a sectional view showing a modified form of the invention.

Referring to FIG. 1, the air motor 10 embodying the invention comprises a cylinder 11 and heads 12, 13 closing the ends of the cylinder. A piston 14 having a piston rod 15 is reciprocable within the cylinder with the piston rod 15 extending through the head 12. Suitable seals 16, 17 provide a fluid tight seal with the rod 15. The motor is held in assembled relation by the use of bolts 18 extending through the head and having nuts 19 threaded thereon.

As will be apparent, each of the heads 12, 13 is substantially similar in structure except for the size of the axial passages therein.

Referring to FIG. 2, head 13 includes a first axial passage 21 that is adapted to receive a projection 22 on the piston 14. When the projection 22 enters the axial passage, it cuts off the flow thereto as presently described. Head 13 also includes a first transverse passage 23 that extends from the exterior of the head into communication with the axial passage 21. A port block 24 having a through passage 25, lateral passage 26, and port 27 aligned with the passage 23 is mounted on the exterior of head 13.

Block 24 has a seal surrounding port 27 which defines a check valve seat 28 against which a check valve 29 is urged by a spring 30 seated against the shoulder 31 in the head 13. An O-ring 32 provides a seal. Head 13 includes a second transverse passage 33 that provides communication to the first transverse passage 23. The head further includes a metering valve seat 34 that cooperates with a metering valve 35 threaded transversely into an opening 36 that extends transversely of the head. Second transverse passage 33 communicates with a second port 37 in the port block 24.

Head 13 further includes spaced second and third axial passages 39, 40 and third and fourth transverse passages 41, 42 that provide communication between the first transverse passage 23 and the second axial passage 39 and between the first transverse passage 23 and the third axial passage 40.

The head also has a metering valve seat 43 at transverse passage 41 that cooperates with a metering valve 44 threaded into the head. The head has a check valve seat 45 at transverse passage 42 against which a valve 46 is yieldingly urged by a spring 47, the position of which is controlled by a threaded member 48. As shown in FIGS. 2 and 3, the position of the metering valve 44 is controlled by a lock nut 49.

The head 12 on the opposite end of the cylinder is similarly constructed except that the axial passage 23 is of larger diameter to accommodate the rod 15 and the projection 50 thereon. For purposes of clarity, the passages in the head 12 have been given identical numbers to the passages in the head 13 with the addition of the prime marks.

The operation of the fluid motor heretofore described may be summarized as follows:

With the piston 14 in the position shown in FIG. 1 when fluid is admitted through the port block 24, it causes the check valve 29 to move away from its seat 28 permitting fluid to flow to the transverse passage 23 and transverse passage 41 through the axial passage 39. The fluid moves the ball 46 away from its seat permitting fluid to flow through the axial passage 40. This forces the piston away from the head 13. As the piston moves to the left as viewed in FIG. 1 and the projection 22 moves out of the axial passage 21, fluid also flows out through the axial passage 21 moving the piston 14.

As the piston moves to the left, the fluid enters the axial passage 21' of the head 12 and flows through the transverse passage 23 past the metering valve 35' passage 33, port 37 and out through one of the openings of the port block 24'.

- This controls the speed of movement of the piston. During this time, the fluid passing into axial passage 40' keeps the ball 46 against its seat. Some fluid flows past the metering'valve 44' and out of axial passage 39'.

As the piston 14 approaches the head 12, collar 50 enters the axial passage 21 This cuts off the flow through the metering valve 25' so that fluid now can only flow through the metering valve 39. This provides a cushioning action.

It can thus be seen that there has been provided a fluid operated cylinder of the air type which combines speed control and cushioning.

In the event that it is desired to omit the cushioning feature from one or both ends of the cylinder, it is only necessary to remove the metering valve 44, 44' and check valve 46, 46' and replace them by plugs 55, 56 as shown in FIG. 7.

Similarly if it is desired to omit the speed control feature, the check valve 29, 29 can be removed and the metering valve 35,35 backed off away from their seat as shown in FIG. 7.

A further feature of the invention is that the metering valve 35, 35' can be moved inwardly into contact with their seats thereby locking the piston in any position to permit adjustment of the mechanism associated with the cylinder without danger of inadvertent movement.

The size of the opening at the seat 34 is at least as great or greater than the size of the opening 21 or the difference in area between the opening 21' and the shaft 15 such that when the valves are retracted or not used, there is substantially no restrictive effect due to the presence of the passages and the motor will operate in the same manner as a standard cylinder of comparable size.

By utilizing the blocks 24, 24' including the passages in associated seats therein, an overall compact structure is achieved which produces and permits the maximum size cylinder to be provided within minimum envelope or confines.

I claim:

1. In an air motor, the combination comprising:

a cylinder;

a piston having a piston rod reciprocable within said cylinder;

at first head at one end of said cylinder through which said rod projects;

a second head at the other end of said cylinder;

each said head having an axial passage therein communicating with the interior of said cylinder; a first transverse passage in each said head extending from the exterior of said head to said axial passage;

a port block mounted externally on each said head and having a fluid port therein;

said port block having a valve seat thereon having its axis aligned with the axis of said first transverse passage;

a second transverse passage in each said head intersecting said first transverse passage;

each said block having a metering valve seat therein between said two transverse passages;

each said head having second and third spaced axial passages therein spaced from said first axial passage;

a third transverse passage in each said head providing comimunication between said first axial passage and said second axial passage;

each said head having a metering valve seat in the area providing communication between said first and second axial passages;

a fourth transverse passage in each said head providing communication between said first axial passage and said third axial passage;

each said head having a check valve seat in transverse passage.

2. The combination set forth in claim 1 including a metering valve in one of said heads cooperating with said first-mentioned valve seat of said head.

3. The combination set forth in claim 1 including a check valve in said first transverse passage in said one head adapted to engage the valve seat of its respective port block.

4. The combination set forth in claim 1 including a metering valve in each of said heads cooperating with said first-mentioned metering valve seat in each of said heads.

5. The combination set forth in claim 4 including a check valve in each said first transverse passage adapted to seat on said valve seat of the respective port block.

6. The combination set forth in claim 1 including a member on said piston adapted to close the corresponding axial passage in one of said heads,

a metering valve associated with said second-mentioned valve seat and a check valve associated with said secondmentioned check valve seat in the respective head in which said member extends at one point in the movement of the piston. g g H 7. The combination set forth in claim 6 wherein said member is on the piston end of said piston.

8. The combination set forth in claim 6 wherein said member is on the piston rod end of said piston.

9. The combination set forth in claim 1 wherein each of said heads has a metering valve associated with said second-mentioned valve seat and a check valve associated with said second-mentioned check valve seat;

said piston having a projection adapted to extend into-coaxial passage of the first-mentioned head; and

an enlargement adapted to extend into the axial passage of said other head as the piston approaches the respective heads.

10. In an air motor, the combination comprising:

a cylinder;

a piston having a piston rod reciprocable within said cylinder;

a first head at one end of said cylinder through which said rod projects;

a second head at the other end of said cylinder;

each said head having an axial passage therein communicating with the interior of said cylinder;

a first transverse passage in each said head extending from the exterior of said head to said axial passage;

a port block mounted externally on each said head and having a fluid port therein;

said port block having a valve seat thereon having its axis aligned with the axis of said first transverse passage;

a second transverse passage in each said head intersecting said first transverse passage;

each said block having a metering valve seat therein between said two passages;

each said head having second and third spaced axial said fourth a metering valve in one of said heads cooperating with said first-mentioned valve seat of said head;

a check valve in each said first transverse axial passage of said head adapted to seat on said valve seat of the respective port block.

11. The combination set forth in claim 10 including a member on each said piston adapted to close the correspondv ing axial passage in one of said heads,

a metering valve associated with said valve seat and acheck valve associated with said secondmentioned check valve seat in the respective head in which said member extends at one point in the move-' ment of the piston. n

12. The combination sF'fBRH in clairri "iTJiiFifiEEEi member is on the piston end of said piston.

13. The combination set forth in claim 11 wherein saidmember is on the piston rod end of said piston.

14. The combination set forth in claim 10 wherein each of a metering valve associated with said secondi said heads has mentioned valve seat and a check valve associated with said second-mentioned check seat,

said piston having a projection adapted to extend into coaxial passage of the first-mentioned head, and

an enlargement adapted to extend into the axial passage of said other head as the piston approaches the respective heads.

15. In an air motor, the combination comprising:

a cylinder;

a piston having a piston rod reciprocable within said cylinder;

at first head at one end of rod projects;

a second head at the other end of said cylinder;

each said head having an axial passage therein communicating with the interior of said cylinder;

said cylinder through which said a first transverse passage in each said head extending from' the exterior of said head to said axial passage;

a port block mounted externally on each said head and hav- P ing a fluid port therein;

said port block having a valve seat thereon having its axis aligned with the axis of said first transverse passage;

a second transverse passage in each said head intersecting third axial passage; each said head having a check valve seat transverse passage; a member on said piston adapted to close the corresponding axial passage in one of said heads; a metering valve associated with said second-mentioned valve seat and a check valve associated with said secondin said fourth second-mentioned head providingcommunication between said first axial passage and said mentioned check valve seat in the respective head in which said member extends at one point in the movement of the piston.

16. The combination set forth iriclairn wherein said member is on the piston end of said piston.

17. The combination set forth in claim 15 wherein said member is on the piston rod end of said piston. 

